Dobbies



Oct. 9, 1962 H. H. sTAuBu 3,057,379

DOBBIES Fi led Jan. 24', 1958 s Sheets-Sheet 1 H. H. STAUBLI Oct. 9, 1962 DOBBIES 5 Sheets-Sheet 2 Filed Jan. 24, 1958 H. H. STAUBLI Oct. 9, 1962 DOBBIES 3 Sheets-Sheet 5 Filed Jan. 24, 1958 United States Patent ()fifice 3,057,379 Patented Oct. 9, 1962 3,057,379 DOBBIES Heinrich Hugo Stiiuhli, Horgen, Switzerland, assignor to Gehr. Staubli & (10., Horgen, Switzerland, a company of Switzerland Filed lien. 24, 1958, Ser. No. 711,076 Claims priority, application Switzerland July 27, 1957 7 Claims. (Cl. 139-71) The present invention relates to a dobby with a pattern card, at least one draw knife and draw hooks associated with the knife and controlled for engagement with the knife according to the pattern.

In known dobbies of this kind the hooks are supported and carried by so-called hook needles in such a manner that during the idle movement of the draw knife those hooks which do not have to be engaged by the draw knife during the next pick are lifted off the draw knife by these hook needles. The hook needles then hold these books in their upper position until the draw knife has returned to that position in which the books have to be controlled again. If an attempt is made to operate dobbies of this kind at high speed, the lifting of the hooks takes place abruptly, resulting in shocks, so that resilient deformations and vibrations occur at the hook ends and may cause faulty control of the hooks. Moreover, signs of wear very soon appear at the lower ends of the hook needles and on the rising rails which move these hook needles upwards.

The present invention aims at eliminating these dis advantages by causing all draw hooks engaged by a draw knife to be lifted away from the .engagement surface of the knife, by a movement of the draw knife, for the purpose of the next control of the hooks in accordance with the pattern. Thus, the hook needles therefore no longer have to lift the hooks, so that the hook needles also no longer have to withstand the aforesaid shocks. The only function still performed by the hook needles is that of retaining those hooks, which do not have to be engaged by the draw knife when it is next drawn out, in their upper inoperative position until the knife has been its forward and backward movement and has returned to its basic postion.

Two embodiments of the invention chose by way of example are particularly described hereinafter with reference to the accompanying drawings, in which:

FIG. 1 is a diagrammatic side view of a double-lift open-shed positive dobby,

FIG. 2 is a plan view of part of the machine shown in FIG. 1, on a larger scale,

FIG. 3 shows the driving mechanism of the draw knives in one particular position, in section on line III-III of FIG. 2,

FIG. 4 shows the corresponding position of the actuating elements for a heald shaft, which is in the upper shed, in section on line IV-IV of FIG. 2,

FIG. 5 diagrammatically illustrates a second embodiment,

7 FIG. 6 shows the associated mechanism for lifting the hooks, and

FIG. 7 is a plan view of part of this mechanism.

In the first embodiment a loom frame 1 carries on the one hand heald shafts 2 upwardly and downwardly movably mounted thereon in a manner known per se, and on the other hand the associated dobby having two plates 3 screwed on to the frame 1. Levers 5 are rockably mounted on a. shaft 4 interconnecting these plates; each of these levers 5 is pivotally connected to a respective pulland push-rod 6 for the movement of one of the said heald shafts, and to a respective baulk lever 7. Draw hooks 8 and 9 co-operating respectively with draw knives 10 and 11 are pivoted each to a respective end of the baulk lever.

The upper knife 10 is mounted on two guiding arms 12 disposed outside the plates 3 and rockably mounted on pivots 13 (FIG. 3) so that the draw knife 10 is moved to and fro along a circularly curved path by pulland push-rods 14. The rods 14 are pivoted to two-armed levers 1S and 16 both rigidly mounted on a shaft 17 rotatably mounted in the plates 3. The two-armed lever 15 is provided with a guiding roller 18 running in a curved groove 19 of a cam disc 20 (FIGS. 2 and 3) which rotates and thereby imparts a reciprocating movement to the lever 15 and also, through the shaft 17, to the lever 16, and this movement is transmitted to the draw knife 10.

The lower knife 11 is mounted on two guiding arms 21 disposed between the plates 3 and rockably mounted on pivots 22, so that the draw knife 11 is also moved to and fro on a circularly curved path by pulland pushrods 23. Like the rods 14, the rods 23 are pivoted to the two-armed levers 15 and 16. The cam disc 20 is outside one of the plates 3 and is fixed to a shaft 24 driven in rotation from the loom through the intermediary of a sprocket Wheel 25.

FIG. 3 shows that by means of the previously described mechanism 12 to 25 the knives 10 and 11 are alternatively moved to the left into a drawn-out position and then back to the right into a basic position in which with the aid of a movement, described hereinafter, of the knives and the hook needles 26 (FIG. 4), the associated hooks are controlled in accordance with the pattern card 48 in a manner known per se through the intermediary of reading needles 49, push needles 50 and rising rails 51.

Movable stop bars 27 always move together with the knives, since they are connected to the knives through the rods 14 and 23 respectively. These movable stop bars co-operate with the ends of the baulk lever 7, and serve to push these ends back into the basic position after the ends have been brought into the drawn-out position by the knives through the intermediary of the hooks and the respective heald shafts have been thereby brought into the upper shed, and to press said ends in the basic position against a fixed stop bar 28 until the hooks have been controlled again for the next pick. In this basic position, the clearance necessary for this control must be present for instance between the knife and the hook 9 (FIG. 4).

If during the next pick for instance the hook 9 shown in FIG. 4 is not to be driven by the knife 11, then said hook must be brought into a position in which a shoulder 29 on the hook is behind a fixed rail 30, and must hold the lower end of the baulk beam against the fixed stop bar 28 in spite of the subsequent leftward swinging movement of the knife 11 and the movable stop bar 27 associated with said knife.

But if the hook 9 is lowered in accordance with the pattern card, then said hook is driven by the knife 11 to the left into the drawn-out position (like the hook 8 in FIG. 4).

The following description shows how all draw hooks engaged with a draw knife are lifted away fro-m the engagement surface of the knife by a rotary movement of the knife before their next control in accordance with the pattern. This rotary movement of the knife at the same time causes the creation and removal of that clearance between the hook and the draw knife which is necessary for the control of the hooks.

The knives 10 and 11 can make an additional movement relatively to the movable stop bars 27; the knives are mounted in the guide arms 12 and 21, and in the rods 14 and 23, respectively in each case rotatably about an axis parallel to the longitudinal direction of the knives, so that for instance the distance between the engagement surface 31 adapted to engage the draw hooks 8, and the associated movable stop bar 27, periodically changes. A lever 32 secured to the knife transmits the rotary movement to said knife. The free end of the lever 32 is guided by'rneans of a stud 33 in a guideway 34 in such a manner that no rotation of the knife 10 occurs during the wholedrawing-out and returning movement of the knife. For this purpose the guideway 34 is of circularly curved shape, the radius of curvature being equal to the length of the guiding arm 12, so that the stud 33 moves exactly parallel to the knife 10. The guideway 3d is rockably mounted on a pivot 35, so as to be able to rotate the knife 10 by rocking movement of the guideway, through the intermediary of the lever 32. The rocking movement of the guideway 34 is derived from the cam disc 20, with the aid of a roller 37 guided in a groove 36 of the cam disc 20- and mounted on an arm 39 secured to a sleeve 38. The sleeve 38 is rotatably mounted on a pivot 38a and is secured to a further arm 40 of which a free bifurcated end embraces a pin 42 secured to a link 41. The link 41 is pivotally connected both to the guideway 34 and also to a guideway 43 for the lower knife 11 which in a similar manner is rotatably mounted in the guiding arms 21 and rods 23 and can be rotated through the intermediary of a lever 44 guided in the guideway 43 which is likewise rockable about a pivot 46.

When the cam disc 20 passes through the position shown in FIG. 3, the knife 11 is in the basic position (see FIG. 4 also). Since at this moment the roller 37 has run on to a hump 47 in the groove 36, the link 41 has been raised slightly whereby the knife 11 has been slightly turned clockwise through the intermediary of the lever 44. The engagement surface 52 of the knife 11 has thus been moved clear of the draw hook 9, through a distance equal to the reading-in clearance. But at the same time the hooks 9 have been lifted off by a support surface 54 of the draw knife I l; this support surface 54 extends away from the engagement surface 52. The draw hooks have pants 55 extending away from their own engagement surfaces and co-operating with the support surface 54. Therefore, before being controlled in accordance with the pattern all the hooks are in their raised position. The required hook needles 26 are also raised in accordance with the pattern, so that the draw knife 11 can then turn counterclockwise and the engagement surfaces of those hooks 9 whose hook needles have not been raised engage the engagement surface 52 of the draw knife 11. At the same time the reading-in clearance is then removed by the rotation of the knife 11. The knife 11 then begins its stroke movement, while the knife It returns to its basic position. The rotation of the draw knife 11 permitting the descent of the selected hooks 9 is produced by the fact that the link 41 is displaced downwards again owing to the further rotation of the cam disc 2%. The shape of the groove 19 in the cam disc at the same time causes the knife 11 to be drawn out towards the left while the knife 10 is moved to the right into its basic position.

During the rotation of the knife 11 in its basic position, the knife 10 is in its drawn-out position (see FIGS. 3 and 4). When the link 41 is now raised slightly, whereby the guideway 34 is also rocked slightly, this has practically no effect on the knife 10, since the free end of the lever 32 of the knife 10 is very close to the pivot 35 about which the guideway 34 is rocked.

Similar processes take place when the cam disc 20 passes through a position offset 180 from that shown in FIG. 3, the hump 45 being under the roller 37. Only the upper knife 10 is temporarily rotated, in order to produce the necessary reading-in clearance and to raise the hooks 8, while the lower knife 11 is not rotated.

Apertures 53 in the plates 3 permit unhindered reciprocatory movement of the knives 10 and 11 and the movable stop bars 27.

FIG. 4 shows that resilient lugs 56 formed as driving members are provided, which make individual connections between the draw knives and each draw hook, permitting those draw hooks that have to be attached to the draw knives in accordance with the pattern to be engaged more rapidly than is possible merely by the force of gravity acting on the draw hooks. If for instance the knife 11 is rotated counter-clockwise out of the position shown in FIG. 4, the lugs 56 drag down those draw hooks 9 which are not held in the upper position by the hook needles. The lowering of the hooks can therefore take place very rapidly, and this also assists in increasing the speed of operation of the machine. Those hooks which are held in their upper position detach themselves readily from the resilient lugs 56. Moreover, these hooks readily reengage in the respective resilient lugs 56 as soon as the knife has returned to the basic position and is rotated clockwise.

The resilient lugs 56 are made for instance of spring steel and are secured to the draw knife. It is clear however that they could equally well be mounted on the parts 55 of the hooks, so that the hooks resiliently attach themselves to the knife.

The invention can also be readily applied to a negative dobby; in this case, the baulk levers 7 are drawn back into their basic position, i.e. to the fixed stop bars 28, and retained there, through the intermediary of the levers 5 by resilient force, and not by movable stop bars 27 as in the previous embodiment.

But that clearance between the engagement surface of a knife and of the associated hooks which is necessary for the control of the hooks need not necessarily be produced by rotation of the knife, but may alternatively be produced and removed again owing to the fact that the knife performs a so-cal-led idle movement. In this case the knife, after having taken the hooks engaged by it back to the fixed stop bar 28, continues its movement for some distance and then reverses its direction and takes with it some of the hooks which have been controlled in the meantime. But in this case also, the raising of the hooks from the knife is effected by the rotation of the knife described with reference to FIGS. 1 to 4.

But the raising of the hooks from the engagement surface of the draw knife can also be effected by a movement of the knife in another manner, as described hereinafter with reference to FIGS. 5 to 7. In the dobby diagrammatically illustrated in FIG. 5 the heald shafts are urged downwards by springs 57 and the knives 58 and 59 are moved by a crank drive 60 through the intermediary of rocking levers 61 and rods 62 and are guided in straight slots 63 in the plates 64. The springs 57 cause those ends of the baulk levers which are not drawn out by a knife to be held against the fixed stop bars 65, and the hooks engaged by the knives to be pulled against their engagement surfaces. As shown in FIGS. 6 and 7, the mechanism for raising the hooks from a knife while the knife is making its idle movement, in order to produce that clearance between the engagement surfaces of the hooks and of the associated knife which is necessary for the control of the hooks, is provided with two levers 66, for each knife, which levers are rotatably mounted on the knife; each lever is connected at one end to a carrier 69 forming a support surface for the parts 67 of the hooks 68. Springs 70 mounted on the knives tend to rotate the levers 66 counter-clockwise with reference to FIG. 6. Stops 71 co-operating with the knives limit this rotary movement in such a manner that the carrier 69 is located underneath the, parts 67 of the hooks engaged by the knife. The levers 66 are also each provided with a projection 72 which co-operates with a stop 73 arranged on the plate 64 as soon as the knife begins to make its idle movement, i.e. as soon as the hooks and baulk lever ends returned by this knife bear against the fixed stop bar 65. The idle movement of the knife causes the levers 66 first to be rotated clockwise by bearing against the stops 73, so that the carrier 69 lifts the hooks off the knives. After the knife has passed its dead point, the lowering of the carrier 69 resulting therefrom permits those hooks which are not supported by hook needles 74 to be engaged by the knife. In this case also, the hook needles 74 serve only to retain in their raised position the hooks that are not to be connected to the knife.

What is claimed is:

1. In a dobby with a pattern card, at least one draw knife having an engagement surface and draw hooks associated with the knife and controlled for engagement with the knife according to the pattern, and means actuated by the draw knife for lifting all draw hook-s engaged with said draw knife away from the engagement surface of the knife upon movement of the draw knife, for the purpose of the next control of the hooks according to the pattern.

2. In a dobby with a pattern card, at least one draw knife having an engagement surface and draw hooks associated with the knife and controlled for engagement with the knife according to the pattern, and means for lifting all draw hooks engaged with said draw knife away from the engagement surface of the knife upon movement of the draw knife, for the purpose of the next control of the hooks according to the pattern, and guiding members for effecting the drawing movement of the knife, said knife being pivotally mounted in said guiding members, and said knife having a support surface extending away from the engagement surface and adapted to lift the draw hooks away from the engagement surface upon pivoting movement of the draw knife in said guiding members.

3. In a dobby with a pattern card, at least one draw knife having an engagement surface and draw hooks associated with the knife and controlled for engagement with the knife according to the pattern, and means for lifting all draw hooks engaged with said draw knife away from the engagement surface of the knife upon movement of the draw knife, for the purpose of the next control of the hooks according to the pattern, and guiding members for effecting the drawing movement of the knife, said knife being pivotally mounted in said guiding members, and said knife having a support surface extending away from the engagement surface and adapted to lift the draw hooks away from the engagement surface upon pivoting movement of the draw knife in said guiding members, the draw hooks having parts extending away from the engagement surface and adapted to lie on the supporting surface of the draw knife.

4. In a dobby with a pattern card, at least one draw knife having an engagement surface and draw hooks associated with the knife and controlled for engagement with the knife according to the pattern, and means for lifting all draw hooks engaged with said draw knife away from the engagement surface of the knife upon movement of the draw knife, for the purpose of the next control of the hooks according to the pattern, and guiding members for effecting the drawing movement of the knife, said knife being pivotally mounted in said guiding members, and said knife having a support surface extending away from the engagement surface and adapted to lift the draw hooks away from the engagement surface upon pivoting movement of the draw knife in said guiding members, the draw hooks having parts extending away from the engagement surface and adapted to lie on the supporting surface of the draw knife, and driving members providing individual connections between the draw knife and each draw hook, whereby the draw hooks are engaged with the draw knife in accordance with the pattern more rapidly than is possible merely by the force of gravity acting on the draw hooks.

5. In a dobby with a pattern card, at least one draw knife having an engagement surface and draw hooks associated with the knife and controlled for engagement with the knife according to the pattern, and means for lifting all draw hooks engaged with said draw knife away from the engagement surface of the knife upon movement of the draw knife, for the purpose of the next control of the hooks according to the pattern, and guiding members for effecting the drawing movement of the knife, said knife being pivotally mounted in said guiding members, and said knife having a support surface extending away from the engagement surface upon pivoting movement of the draw knife in said guiding members, the draw hooks having parts extending away from the engagement surface and adapted to lie on the supporting surface of the draw knife, and driving members providing individual connections between the draw knife and each draw hook, whereby the draw hooks are engaged with the draw knife in accordance with the pattern more rapidly than is possible merely by the force of gravity acting on the draw hooks, said driving member consisting of resilient lugs.

6. In a dobby with a pattern card, at least one draw knife having an engagement surface and draw hooks associated with the knife and controlled for engagement with the knife according to the pattern, and means for lifting all draw hooks engaged with said draw knife away from the engagement surface of the knife upon movement of the draw knife, for the purpose of the next control of the hooks according to the pattern, and a carrier rotatably mounted on the knife adapted to be rotated during the idle movement of the knife to lift the draw hooks away from the engagement surface of the knife.

7. In a dobby with a pattern card, at least one draw knife having an engagement surface and draw hooks associated with the knife and controlled for engagement with the knife according to the pattern, and means for lifting all draw hooks engaged with said draw knife away from the engagement surface of the knife upon movement of the draw knife, for the purpose of the next control of the hooks according to the pattern, and guiding members for effecting the drawing movement of the knife, said knife being pivotally mounted in said guiding members, and said knife having a support surface extending away from the engagement surface and adapted to lift the draw hooks away from the engagement surface while the draw knife is making its idle movement upon pivoting of the draw knife in said guiding members.

References Cited in the file of this patent UNITED STATES PATENTS 2,815,044 Staubli Dec. 3, 1957 FOREIGN PATENTS 657,967 Germany Mar. 18, 1938 427,774 Great Britain Apr. 30, 1935 

